https://github.com/satyr/coco/issues/91

noret.co

{Fun, Unary} = Coco.ast

uplus = -> it instanceof Unary and it.op is \+

<- Coco.on \compile
<- it.ast.traverseChildren ..., true
# +->
if uplus it and (fun = it.it) instanceof Fun
  delete it[k] for k in it
  fun = it <<< {fun.__proto__, ...fun}
# <-+
else if uplus it.head and not it.tails.1 and
        (call = it.getCall!) and (fun = call.args.0) instanceof Fun
  callee = it.head.it
  # <-+ f x, ...
  if callee.getCall!
    {call.args} = that
    break if a.filler for a, pos of call.args
    call.args[pos] = fun
    callee.=head
  it.head = callee
else return
Object.defineProperty fun, \void value: true
void